Police warn of 'suspicious' packages as more explosions rock Austin

AUSTIN, Texas - Local and federal authorities rushed Monday to respond to a pair of explosions in Austin, Texas, just days after another blast fatally injured a man in the Texas capital.

These three explosions at homes or in residential areas, which have not all been linked by authorities, set officials and residents alike on edge, with police urging residents to call 911 rather than opening unexpected packages.

The explosions Monday came 10 days after a package on the front porch of a northeast Austin home exploded. Police said 39-year-old Anthony Stephan House was critically injured in the March 2 blast and later died. At the time, police said his death was "suspicious" but believed it was an isolated incident with no continuing threat to the community.

On Monday, however, a pair of blasts rocked other areas of the city while it hosts South by Southwest, a 10-day music, film and technology conference that draws tens of thousands of visitors each year.

Early in the morning, authorities responded to a package explosion at a home on the east side of Austin and found two injured victims inside: A 17-year-old male and an adult woman. The 17-year-old died, while the woman was taken to the hospital with injuries, and police said they were investigating that incident as a homicide.

Five hours later, another explosion was reported in another residential area, this time in the city's southeast region. A woman in her 70s was taken to an area hospital "with serious potentially life threatening injuries," according to the Austin-Travis County Emergency Medical Service.

Austin Police Chief Brian Manley - who reportedly was on the scene of Monday's first explosion when he was called to the second - warned residents to avoid opening unexpected packages.

"If you receive a package that you are not expecting or looks suspicious, DO NOT open it, call 911 immediately," he tweeted.

Authorities had said they believe the first two explosions are linked. Both took place in the morning hours, and in both cases, the package was not delivered through the U.S. Postal Service, authorities said.

In addition, both of the homes belonged to African Americans, Manley told reporters Monday morning.

"So we cannot rule out that hate crime is at the core of this; but we're not saying that that's the cause as well," the police chief said.

Nelson Linder, president of the NAACP of Austin, said the person injured in the third explosion was not African-American.

"There's always concern about that," Linder said of a potential hate crime, "but other than the two first victims' race, there's no evidence to say they were one at this time."

Still, he said, people are "very concerned and feel very vulnerable."

The FBI field office in San Antonio said it was assisting Austin police with the investigation. Michelle Lee, a spokeswoman for the FBI, said they were "definitely not ruling out" a hate crime, due to the race of the first two victims. She added Monday afternoon that it was "too early to tell whether or not number three was related."

Isaiah Guerrero, 15, said he was spending the first morning of his spring break making music on his computer when he heard the third explosion go off just before noon Monday.

"It sounded like two cars hit each other, you know? Like, rammed each other," Guerrero said.

The house shook, and so did his body, the teenager said. Guerrero then climbed up a tree and on top of his house. Within minutes, police and fire officials swarmed the scene, closing off streets. Guerrero, who lives behind the house where the bomb went off, said he couldn't see the damage to the front of the house.

He echoed law enforcement officials in warning the public to pay attention to things like packages, "especially if you didn't order something," he said. Guerrero added: "I expected my spring break to be peaceful, not harmful."

The Bureau of Alcohol, Tobacco, Firearms and Explosives said Monday it was dispatching members of its National Response Team (NRT) to help respond to the explosions. According to the agency, this group activates for "significant fire and explosion incidents," considered those that are either large in scale or particularly complicated due to the size or scope.

In the past, that has included responding to the West, Texas, plant fire in 2013; a string of church fires in Texas; and the bombings in Oklahoma City and at the 1996 Olympic Games in Atlanta. The NRT works with other investigators to reconstruct scenes and determine what caused the fires or explosions; in cases involving bombings, the team also searches for evidence to be used in any prosecution that may follow.

Manley, the Austin police chief, said local and federal law enforcement agencies would ensure "every stop would be pulled out" to solve the cases.